. >>> president obama rallied 12,000 supporters at a park in debver. -- in denver. he accused mitt romney of misleading voters and joked it wasn't the real mitt romney on stage with him last night. mitt romney made a surprise appearance at a meeting in denver. his sons introduced him. mitt romney referred to trickle down government and said he doesn't think that is something the american people believe in. twitter says last night's debate was the most tweeted about event in twitter's history. mitt romney was the clear winner according to twitter. they found 47,000 tweets with the word romney in there, versus 30,000 referring to president obama. in 30 minutes, what a lot of people are talking about, mitt romney's comment about cutting funding for pbs. a local station tells us how the viewers are responding. >>> fbi investigating the death of u.s. ambassador chris stevens, spent 12 hours at the scene of the attack. u.s. ambassador chris stevens and three others were killed one month ago. attorney general eric holder said the probe has been ongoing and it took till now